What kind of car speaker system are you trying to link with? Is it Ford Sync? Really, they should all work similarly, and so the system should have the option to discover Bluetooth devices. By doing this and then on the phone, going to Settings > System > Bluetooth, you can switch the BT status to "On", and it will search for nearby devices. If it works, your car's system should show up on the list.
I recently paired mine (back on NoDo) to a Kia with Bluetooth. Once the handset is paired with the car, it should override the car audio (radio or CD) once you start playing music OR make/receive a phonecall. I was totally impressed!